Submillimetre-waves

Need for speed and subtlety in security screening

In today’s world, the expectations of security are often at odds with the inconvenience that conventional security measures impose on the public. Furthermore, traditional screening methods such as metal detectors fail to detect non-metallic items, and often produce such a large false alarm rate that the entire screening process comes to a grinding halt.

Submillimetre-waves

Asqella’s camera technology operates at the so-called submillimetre-wave region (Often called also terahertz region). This ¨final frontier¨ of the electromagnetic spectrum has been relatively little explored due to the lack of affordable sensing technology.
The submillimetre-wave spectral range lies between the infrared and microwave regions of the electromagnetic spectrum. As the name suggests, this type of electromagnetic wave has a wavelength between 0.1 mm and 1 mm.

The atmosphere is hostile to these wavelengths: there are a number of extremely strong water vapour absorption peaks in the submillimetre-wave range, which severely limit the transmission of these wavelengths over any significant distance. Common clothing materials are relatively transparent at the submillimetre-wave range, allowing for detection of concealed objects.

The human body also naturally emits submillimetre-waves, albeit very weakly – some 100 times less than in the infrared range.